Inking device



July 10, 1962 c. A." CHRISTOFF' INKING DEVICE 2 Sheets-Sheet i Filed April 11, 1960 FIE l FIE E July 10, 1962 c, c ls'roF 3,043,214

INKING DEVICE Filed April 11, 1960 2 Sheets-Sheet 2 4/ 7 33 flwunn m: m: Z

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United States Patent 3,043,214 INKING DEVICE Chris A. Christofi, San Gabriel, Califi, assignor to Clary Corporation, San Gabriel, Califi, a corporation of California Filed Apr. 11, 1960, Ser. No. 21,370 6 (llairns. (Cl. 101-97) This invention relates to printing devices and has particular reference to improvements for applying ink to the type characters of a high speed continuously rotating type drum.

One means for transferring a type character to a record medium or strip requires the placing of an ink transfer ribbon between the type characters and the record strip, but this means of transfer requires the addition of means for properly guiding and advancing the ribbon, and with a high speed printer in constant use, the wear on the ribbon would require frequent changes.

A second means for transferring type characters to a record strip comprises an ink well for applying ink to an intermediate means, which being in contact with said drum coats the characters with ink in preparation for a print operation. This inking means becomes unsatisfactory when the printer is used in devices subject to rocking or other unstable motion as found on airplanes, boats, missiles, etc., due to the splashing of the ink and the uneven distribution of the ink to the intermediate means.

A third means, of which the present invention is an improvement, comprises an ink supply pad having direct contact with the type drum or an intermediate member such as an ink transfer roller. Although this means of ink supply is generally satisfactory in most environments, the constant friction between the pad and the drum or between the pad and the intermediate member will quickly deteriorate the pad and also, in time, the adjacent member.

One object of the present invention is to provide an inking pad arrangement for a rotary drum type printer which will allow the printer to be mounted in a vehicle or the like which is subject to rocking or unstable motion, without slopping of the ink and without varying the distribution of the ink on the type drumz Another object is to eliminate the frictional engagement between the pad and the intermediate roller of a printer of the foregoing type, thereby greatly increasing the life of the ink pad.

Another objectis to provide a means for removing excess ink from the drum thereby eliminating accumulation of ink deposits around the type characters and uneven printing.

These and further objects and advantages of the invention will be more readily understood when the following description is read in connection with the accompanying drawings, in which:

FIG. 1 is a longitudinal sectional view of a high speed printer embodying the present invention.

FIG. 2 is an enlarged sectional view illustrating some of the mechanical means for driving the type drum.

FIG. 3 is an enlarged fragmentary sectional view illustrating the relationship between the internal gear, the external gear and the type characters.

FIG. 4 is a plan view of the inking device and is taken substantially along the line 44 of FIG. 1.

FIG. 5 is a sectional View taken along the line 5-5 of FIG. 4.

FIG. 6 is a fragmentary sectional view showing a modified form of the invention.

The particular printer illustrated in connection with the present invention is disclosed and claimed in the patents to E. O. Witt et al., Patent No. 2,915,968, issued on December 15, 1959, and the C. A. Christoff et al., Patent No. 2,910,936, issued on November 3, 1959. Therefore, for the sake of brevity, only those portions of the printer which embody the present invention or cooperate therewith will be illustrated and described herein. It is to be understood, however, that the invention could be equally well applied to other types of rotary drum printers.

Describing first the printer, the latter comprises a hollow drum 11, FIGS. 1 and 2, having afiixed at its extreme ends external gears 12 (only one shown). Said drum also comprises a plurality of adjacent circumferentially extending rows of type characters spaced therearound, which may be more easily seen in the aforementioned Patent No. 2,915,968.

The drum 11 and gears 12 are supported by ball bearings 13 on eccentric members 14 (only one shown). Therefore, the drum 11 and gears 12 are concentric to the axis formed by the intersection of the vertical center line and the line A, which is the axis of the eccentric member 14, but are eccentric to the axis formed by the intersection of the vertical center line and the line B, which is the axis of the printer drive shaft (not shown).

A pair of internal gears 15 (only one shown) are mounted in printer support frames 16 concentrically of the printer drive shaft axis B, and in line with the external gears 12 so as to mesh with the same.

The ratio between the teeth of the gears 12 and 15 is such that as the eccentric members rotate the eccentric axis A about the axis B, the external gear will be retracted a specific amount equal to one type character space on the drum.

The motion of the drum as above described is commonly called a hypocycloidal motion whereby a point or a character 17 (FIG. 3) will approach the print point P (FIG. 1) through a hypocycloidal curve as indi cated at 18. It will be seen that as a type character reaches the cusp of its outward travel, it will be moving substantially radially outward. If, at this time, a platen 119 is positioned inwardly toward the drum 11, by means not shown, a printing contact with the paper 20 will occur.

The paper is suitably guided from a supply roll (not shown), past the drum 11 and upwardly along the side of a guide block 200 for the various platens.

To supply ink to the type characters 17 of the drum 11 there is provided a transfer roller 19, FIGS. 4 and 5, which is rotatably supported at opposite ends through bushings 21 by leaf springs 22. Each spring 22 is rigidly secured between an adjustment frame 23 and a hold down bar 24 through screws 25, whereby said spring will hold said roller in constant engagement with the drum 11. The adjustment frame 23 is slidably mounted through screw and slot combinations 26, on a cover plate 27. The cover plate and a gasket are secured to an ink supply container 28 by screws 33.

The container 23 is provided with ink absorbing packing 29 of some suitable material such as felt and a top pad 31 of the same material but covered with a screenlike layer of nylon or similar material to prevent tufting of the pad due to the engagement of the roller 19.

The packing 29 and 31 is held in position by a frame plate 32 which is integral with the adjustment frame 23, said plate having an opening 30 through which the roller 19 contacts the pad 31. The plate 32 acts similar to a pressure plate on the packing in that as the roller 19 disengages the pads, the relief of pressure on the pads will hasten the return of ink to the point of pick up.

The ink supply for the packing is entered through an opening 34 in the cover plate 27, said opening having a cover plate 35 to prevent dust and dirt from falling through the opening onto the ink pad.

For cleaning the drum 11 of any exces ink accumulated thereon, there is provided in constant engagement 'ink from the drum 11.

The functioning of the ink transfer roller 19 is that as V the drum 11 reaches its lower position in its hypocycloidal movement, it will have depressed said roller into contact with the pad 31, as shown at 39 of FIG. 5, thereby eliminating practically all of the frictional engagement between the, roller and the pad. This engagement is only momentary and as the drum continues it moves upward allowing the transfer roller to retract out of engagement with the pad 31.

As the print drum continues around past the print point the bristledroller 36, which is held in frictional rolling engagement with surface of the drum, will wipe the excess That is, since the bristles are helically arranged and extend radially from the roller, the ink will be wiped laterally across the drum, dropping oif at the end onto the pad 31. The bristles are preferably formed of a flexible material'such as nylon plastic or theliket The roller 36 is a necessity in this type of printer, in that ink is applied to all of the type characters on the drum but only one character out of each row is used during a print cycle. Thus, if the drum is not cleaned, the characters that are not used would soon build up an accumulation of ink so great, that upon a print they 7 would transfer an unintelligible blot of ink onto the paper. Also, the bristles 136 are eifective to enter and remove ink from the spaces within the type characters thereby preventing accumulation of ink at such points.

The top plate 27 (FIGS. 4 and S) has two upwardly.

extending edges 41 whose curved edges 42 rest against a shrouding 43 (FIG. 1) on the pn'nteigwhose constructionmay be more clearly seen in the aforementioned Patent No. 2,910,936.

After the inking unit has been placed in position as shown in FIG. 1, final adjustment may be made by turning apair of adjustment screws 44. The screws 44 are loosely mounted in upwardly extending ears 45 of the top plate 27 and are held thereby clip springs 46. The screws are then threaded into upwardly extending ears 47 of the adjustment plate 23, so that by turning the screws 44 the platewill, through the screw'and slot combinations 26,: move the rollers 19 and 36 back and forth for final adjustment.

That is, the plate 23 is preferably adjusted so that the transfer roller -19 is caused by the drum 11 =to'lightly touch the top surface of the pad 31 when the roller is at the lowermost point of its movement- Any excessive pressure by the roller'19 against the pad'would cause an .excess transfer of ink and undue wear of the pad. However, such adjustment serves as' a means to control the amount of ink transfer. "That is, as the pressure of the roller against the pad is increased a heavier inking will result. I For best results, it has been found desirable to wrap the roller 19 with a layer 19a of felt or rubberto facilitate transfer of ink;

, A leaf spring 48 mounted on the front of the container 28 is provided so that when a door 49 of the printer is closed itwill apply pressure against the spn'ng'to thereby hold the edges 42 against the shrouding;

' Normaly, the: ink pads 29' and 31 have sufiicient resiliency to continually maintain the upper surface of the former in line with the under surface of the plate 32 as ink is depleted fromthe pads. However, the construction shown in FIG; 6 could be resorted to in the event the ink pads tend to lose their resiliency or sa Here, a resilient leaf spring 50 is attached by a screw 51 to the floor of the-container 28. The spring is formed with an upper level 52 which extends under the upper pad 31to yieldably hold, the latter against the under surface of. th plate 32. Holes 53 are formed in the spring to permit transfer of ink therethrough from one pad to another.

If desired, the roller 19 and the ink transfer layer 19a thereon may be split longitudially into two or more separated sections, as indicated by the dot-dash lines 54 (FIG. 4) to cooperate with similarly separated ink pads, enabling differently colored inks or different types of ink, such as magnetic ink and'standard printing ink, to be applied to the different roller sections. In thiscase, the container 28 and the ink supply pads therein would likewise be split and separated into correspondingly aligned sections. In addition, the'bristles 136 of the roller 36 would also preferably be split and separated in line with the separations of the two sections of the roller 19 or the ink transfer layer 19:: in order to prevent lateral transfer of ink between such sections.

Although the invention is described in detail and therefore certain specific terms and languages are used herein, it is to be understood that the present disclosure is illustrative rather than restrictive and that changes and modifications may be made without departing from the spirit or scope of the invention as set forth in the claims appended hereto.

Having thus described the invention, what is desired to be secured by United States Letters Patent is:

1. In a printing device including a printing drum having a plurality of type characters therearound, means for moving said drum about its center, means for efiecting an impression of a selected one of said type characters against a record medium, and means for applying a coating of ink over said type characters, a roller for removing accumulated ink from said type characters, said roller comprising a helical row of flexible radially extending bristles, and yieldable means rotatably supporting said roller in engagement with said drum whereby said drum engages said bristles to rotate said roller.

2. In a printing device including "a printing drum having a plurality of type characters therearound, means for moving said drum about its center, means for elfectingan impression of a selected one of said type characters against a record medium, and means for applying a coating of ink over said type characters, a roller comprising a helically arranged row of radially extending bristles, means supporting said'roller for rotation about an axis parallel to the axis of said drum, and means for yieldably pressing said roller into frictional engagement with said drum whereby said drum engages said bristles to rotate said roller to cause said bristles to remove accumulated ink laterally from said type drum during rotation of said roller by saiddrum.

3. In a printing device including a printing drum having a plurality of different type characters therearound, means for oscillating the center of said drum while rotating said drum about said center, means for efiecting an impression of a selected one of said type characters against a record medium, and means for continuously applying a film of ink over said type characters, a roller, said roller comprising a helical row of radially extending bristles, bearings on opposite ends of said roller supporting said roller for rotation about an axis substantially parallel to the axis of said drum, and means for independently urging said bearings toward said drum whereby to cause said drum to rotate said roller, said bristles being effective to remove accumulated ink from said type characters upon rotation of said roller.

4. In a printing device including a printing drum havingta plurality of diiferent type characterstherearound, means for oscillating the center of said drum while rotating said drum about said center, and means effecting an impression of a selected one of said type characters against a record medium at a predetermined point in said oscillation, an inking device for said drum comprising an ink transferring roller, means supporting said roller in pad in said container, and means supporting said container in juxtaposition with said roller whereby said roller engages said inking pad during oscillation of said drum away from said record medium and disengages said inking pad during oscillation of said drum toward said record medium.

5. In a printing device including a printing drum having a plurality of different type characters spaced therearound, means for guiding a record medium in juxtaposition with said drum, means for moving the center of said drum in an orbital path toward and away from said record medium while rotating said drum about said center to cause said type characters to move at a rate such that a new type character is presented to said record medium during each orbital movement of said drum center, and means for impressing a selected type char acter against said record medium, an inking device for said drum comprising an ink transferring roller, means yieldably supporting said roller in rolling engagement with said drum, an ink absorbent body, and means supporting said body in juxtaposition with said roller whereby said roller engages said body during movement of said drum toward said record medium and disengages said body during movement of said drum away from said record medium.

6. In a printing device including a printing drum having a plurality of type characters therearound, means for guiding a record medium in juxtaposition with said drum, means for oscillating the center of said drum toward and away from said record medium while rotating til 6 said drum about said center, and means for selectively effecting an impression of one of said type characters against a record medium at a predetermined point in said oscillation; an inking device for said drum comprising an ink transferring roller, spring means supporting said roller in continuous engagement with said drum, a cleaning roller comprising a helical arranged Wiping device, spring means supportnig said cleaning roller in continuous engagement with said drum, an ink reservoir, an ink storing medium in said reservoir, and means supporting said ink reservoir in juxtaposition with said trans fer roller whereby said transfer roller engages said ink storing medium during oscillation of said drum toward said medium and disengages said medium during oscillation of said drum away from said storing medium, said oscillation of said drum acts to rotate said cleaning roller to remove accumulative ink laterally from said type drum.

References Cited in the file of this patent UNITED STATES PATENTS Re. 13,400 McCoy Apr. 9, 1912 1,126,732 Drake Feb. 2, 1915 1,826,801 Littleford Oct. 13, 1931 2,265,856 Reed et a1. Dec. 9, 1941 2,714,365 Rowlands Aug. 2, 1955 FOREIGN PATENTS 1,905 Great Britain of 1855 

